Thank you very much! Yes, your answer helped me getting an objective opinion on the matter :).
You were at your body weight for your height and now you have lost approximately 6kg (13 lbs). For your age you should be consuming 2000-2200 calories per day. Suggest eating yogurt, or drinking milk with the fruit at night so you have a protein source in the meal. You need to increase the food you are eating at breakfast and lunch. Try snacking between meals and especially around dinner time at work so you get more calories in, too. Recommend eating a Heart Healthy diet which will give you the nutrients, vitamins and minerals your body needs, gain weight slowly, and help with possibly preventing future disease states. Heart Healthy diet which is a moderate fat diet and a moderate fat diet means = using polyunsaturated (omega 3, corn oil, nuts, etc) fats and monounsaturated (olive oil, canola oil, peanut oil, etc) fats, no saturated fats (high fat snack foods, butter, fat spreads) and no trans fats. Eat low fat meats (chicken, fish, loin of pork) or non-meat sources (soy products, nuts), low fat vegetarian combinations (rice & beans, pasta & beans, low fat cheese & pasta), low fat and substitute dairy products (1% milk, low fat/fat free yogurts, low fat soy milk/soy yogurt), use plant oils, non trans-fat margarines, and eat a lot of fruits and vegetables. Eat daily high fiber breads and cereals (oatmeal). Hoped this helped you.